I use magnetic snaps in all my bags.
When you open the magnetic snap package there will be both a male and female snap each with 2 prongs on backside, along with 2 small brass circle templates. (The circle “template” shows where the prongs will be and the center dot is where the magnet will be.)
I always use Trimtex to “anchor” the snaps to the fabric.
1. Trace 2 circles onto the Trimtex (I use approx. quarter size thread spool).
2. Center the brass circle template and mark the two slots and circle dot onto the Trimtex... then cut the Trimtex circles out.
3. Check the alignment of Trimtex circles to ensure the snaps will close easily. Fuse these Trimtex circles to the wrong side of the corresponding pocketbook lining (where you want the snaps to meet).
4. Use a seam ripper and carefully insert point and rip along the small slot mark (not too much... you just want slot long enough for the prong to fit through).
5. From the right side of the fabric, insert the prongs into the slots.
6. Take one of the brass circle templates and slide it over the prongs (sticking out on Trimtex side). Using a hard surface and flat side of closed scissors, carefully fold each prong so they lay snug across the center of the brass circle. And one half of the magnetic is attached.
Following the same directions, attach the other magnetic snap through the corresponding Trimtex circle.
Hope these directions are clear enough.